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Overview

The EBP demo viewer aims at showing the scope and potential of the EBP project and its future developments. It is, therefore, solely a very first insight about the possibilities of the collaborative work of European on-line bird recording schemes under the auspices of the EBCC.

The EBP demo viewer shows animated maps depicting the week-by-week distributional patterns of 105 species in seven years (2010-2016) at a resolution of 30x30 km. A total of five types of species maps and four of climatic variables are shown. Two animated maps of any species or climatic variable, year and type can be selected to be shown simultaneously for direct comparison.

Moreover, the option "All years", in the year dropdown list, allows the visualization of the overall seasonal patterns of bird distribution and the climatic variables averaged across the different years of available data. All in all, therefore, more than 20.6 million different map combinations are available to choose from.

Note that you can either select natural years (for example “2014”) or July to June interannual cycles (for example “2015/16”). In the latter, the time series starts at week number 27 of the first year (2–8 July), and finishes in week number 26 of the following year (25 June – 1 July). When selecting natural years the time series starts in week number 1 (1–7 January) and finishes in week number 52 (26–30 December).

Maps

The species maps shown in the EBP demo viewer are based on 205 million bird records submitted between 2010 and 2016 to the on-line bird recording portals run by the project partners. These records were subsequently aggregated by week and 30x30 km square (based on the European Environment Agency reference grid ETRS89-LAEA) summarizing information on the number of observations of each species, the number of counted birds and the recording effort (number of complete lists and total number of records and observers). Four of the species maps (occurrence, traces, counts and phenology) reflect, in different ways, the raw information contained in the aggregated data, while the fifth one (corrected regional occurrence) uses various analytical procedures to account for heterogeneity in observational effort and species reporting rates.

In all cases, only those 30x30 km squares including terrestrial areas are shown in the maps.

Occurrence map

These maps show the 30x30 km squares where the selected species was recorded or not each week. Note that not all species detected end up being reported and, thus, the absence of records in a given square does not automatically mean that the species was not observed there.

Traces map

These maps show the 30x30 km squares where the selected species has been recorded during each week but also during the two previous ones, enhancing the visualization of rapid temporal changes in distribution and their “traces” over time. Note that not all species detected end up being reported and, thus, the absence of records in a given square does not automatically mean that the species was not observed there.

Counts map

These maps show the maximum count recorded for the selected species in each 30x30 km square and week (in "All years" maps, the average of the maximum count of each year is shown). Note that the original counts used to obtain these figures mostly refer to casual counts or rough estimates of the number of birds detected in a given site and date. Only rarely they refer to formal censuses or exhaustive counts. These maps, therefore, only show a rough approximation of the real variability in bird numbers across space and time. Also take into account that not all species detected end up being reported and, thus, the absence of records in a given square does not automatically mean that the species was not observed there.

Corrected regional occurrence (CRO) map

These maps make use of a complex set of spatial and temporal aggregation and smoothing procedures to account for differences in observational effort and reporting activity of the observers (click here for further details). They are specifically intended to help visualize large-scale temporal changes in bird distribution and thus they should not be interpreted at a local scale. For each 30x30 km square and week these maps depict the estimated regional frequency of occurrence of the selected species. Modelling the spatial and temporal dynamics of bird distributions is one of the main but challenging objectives of the EBP project. This work is underway and, therefore, it has to be stressed that the maps shown here are very preliminary.

Phenological map

These maps depict the phenology of the selected species in seven different geographical sectors according to the percentage of 30x30 km squares where the species has been recorded in each sector and week.

Data accuracy and interpretation

Each on-line bird recording scheme submitting data to the project has its own data validation protocols to deal with potentially erroneous observations. Moreover, additional data quality checks are conducted at the EBP level. However, overall, the EBP demo viewer synthesises more than 205 million bird records in about 44,000 weekly maps. These are too large numbers to completely discard the possibility that some erroneous observations could still be present in some maps.

The possible existence of some erroneous records or counts, however, shouldn't distort the overall large-scale patterns of bird distribution shown in the viewer, which is the ultimate interest of the EBP project.

Rather than the possible presence of a few erroneous observations, it is the interpretation of the maps itself that requires an important cautionary note. On-line bird recording portals mainly obtain data from the relatively unstructured but intensive and widespread activities of birdwatchers. This means that surveying effort can differ largely from one area to another (even very close ones) or from one week to the next. It is even more relevant that the willingness to report a given species can vary significantly among sites, weeks and the rarity of the species (observers tend to report more often a given species in areas or periods of the year where it is less usual or common). Accordingly, a lack of records of a given species in a given surveyed square and week does not automatically mean that the species was not observed there (it may have been observed but not reported).

In many cases, the advice of an expert and further analyses may be required to draw sound conclusions from these maps. The EBP, therefore, can't be made responsible of the inadequate use of the information contained in the viewer or its interpretation by third parties (see also Disclaimer).

Note that records of rare species which don't seem unreliable but which are still under formal revision by the corresponding Regional or National Rarities Committees are also included in the maps. Certainly, some of these records could end up being not accepted by the respective committee. However, the reviewing protocols differ among committees and partners and in some cases the process can take several months and, therefore, not including of these observations could artificially alter the seasonal patterns of distribution of these species. In any case, these considerations should always be taken into account when interpreting the maps of these particular species.

Data use by third parties

The EBP demo viewer is just the first step towards the creation of the future EBP data repository infrastructure and associated website. In due time, the products of the EBP and other relevant information will be fully accessible to the public in its website.

It is anticipated that research and production of products based on EBP data will largely involve EBP partners. Others may be involved but they should not normally lead research projects or other work.

Once the EBP website is available, applications to access the original partner’s aggregated data contained in the EBP data repository may be made by third parties through a specific data request module. Note that depending on the nature and source of the data extraction request it may be subject to a fee.

Disclaimer

This website is hosted by the Catalan Ornithological Institute on behalf of the EuroBirdPortal project (EBP), an initiative of the European Bird Census Council (EBCC), a not-for-profit organization located in Nijmegen, The Netherlands.

Using this website requires agreeing with the following:

The content, information and maps shown in this website are provided in good faith and for informational purposes only. They do not constitute any advice or recommendation in itself and no warranties are given regarding the same.

EBCC is not responsible for errors that may contain the information provided on this website or the consequences that may result from the use or interpretation thereof.

The boundaries, colours, denominations or other information shown on maps do not imply any judgement on the part of EBCC concerning the legal status of any territory, or the endorsement or acceptance of such boundaries. Users must observe the copyright and licensing provisions included with all maps.

Acknowledgements

The maps shown in the EBP demo viewer are possible thanks to the activity of several thousands volunteer birdwatchers that submit their observations to the on-line bird recording schemes run by the EBP partners. Without their continuous contribution in time, effort and expertise the EBP project would be unfeasible. Our big thanks to all of them.

The financial support of the Swiss Ornithological Institute has been decisive for the implementation of the demo viewer and to undertake the first steps of the EBP project.

Preparation of the corrected regional occurrence (CRO) maps

The observational effort and the willingness to report a given species are unevenly distributed in space and time. Hence, it is important to produce maps that can account for such sources of variation and uncertainty.
As a first step to produce these maps, we used a set of spatial and temporal aggregation and smoothing procedures. The objective was to create maps intended to help visualize large-scale spatiotemporal changes in bird distribution rather than details on bird distribution dynamics at fine spatial and temporal scales.
First of all, data was aggregated using spatial and temporal rules to increase the sampling effort and the amount of bird occurrence information available when/where the local sampling effort was insufficient. In a second step, a spatial smoothing approach was applied to calculate the expected frequency of occurrence of each species over a predefined area in the neighbourhood.

1. Estimation of an adequate sampling effort and calculation of reporting rates based on a spatial and temporal aggregation procedure

The total number of observations reported for all the species during a given week and in a given 30x30 km square has been used as an indirect estimate of sampling effort. For each species, reporting rates were calculated in each square and week as the percentage of observations of the species relative to the total number of observations. To calculate consistent reporting rates, however, a minimum adequate sampling effort had to be used. To estimate such adequate sampling effort, reporting rates calculated in all 30x30 km squares and during the different weeks along the year were plotted against the total number of observations in those squares and those weeks. As expected, the variability in estimated reporting rates decreased with increasing sampling effort, i.e. with an increasing number of observations used to estimate it. The adequate sampling effort was defined as the total number of observations above which the reporting rate became stable. Reporting rates were then estimated at different spatial and temporal resolutions depending on the sampling effort in each square and each week.

If the sampling effort was sufficient, reporting rates were calculated at fine spatial (30x30 km) and temporal (1 week) resolutions. If the total number of observations in a focal 30x30 km square and week was below the adequate sampling effort, bird observations reported during the previous week and/or in squares around the focal square were also added. Such inclusion of additional bird observations increases the sampling effort but decreases the spatial and/or temporal resolution at which reporting rates are estimated. In order to find the best compromise between sampling effort and resolution, this aggregation procedure was carried out in an iterative way by using a gradually increasing number of squares in the neighbourhood until the adequate sampling effort was reached. The maximum number of squares used to increase the sample of bird observations from the neighbourhood was limited to a radius distance of 120 km. In poorly sampled regions or during certain periods of the year, the adequate sampling effort was not reached using this maximum radius distance and the reporting rates were impossible to estimate.

The reporting rates calculated across a range of spatial and temporal resolutions were then allocated to each 30x30 km square and to each week (i.e. the basic spatial and temporal resolutions of the EBP demo viewer) irrespective of the spatial and/or temporal level of aggregation used for the calculation.

Average level of the spatial and temporal aggregation used for each 30x30 km square and year (the lower, the better the resolution).

2. Spatial smoothing procedure

For each 30x30 km square and each week, the reporting rate estimated above was converted into a binary species presence/absence variable: 1 when reporting rate was higher than 0 (presence) and 0 when reporting rate was equal to 0 (absence). It is important to note that this conversion is based on reporting rates that were previously estimated for each square and each week in a consistent way according to a spatial and temporal aggregation procedure so that sampling effort was considered as adequate to estimate species presences and absences.
Based on this binary information, a “corrected regional species frequency of occurrence” value was calculated for each 30x30 km square and each week as the proportion of squares where the species was estimated to be present within a 250 km radius distance (100 km for terns, shorebirds, ducks, geese and swans). The value was only calculated when there were at least 50% of squares with estimated reporting rates within the 250 km radius distance. Note that in the viewer maps areas where estimated occurrences are more unreliable due to data scarcity (Low Resolution areas) can be shaded off by turning on the corresponding layer.

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